Certain embodiments described herein are generally related to digital imaging, and more specifically, to Multiplexed Fourier Ptychographic imaging systems and their components, and Multiplexed Fourier Ptychographic imaging methods.
Ptychography imaging involves collecting lower resolution intensity images and reconstructing them into a higher resolution image. Over the past two decades, ptychographic imaging has been used in a variety of regimes to produce high-resolution, wide field-of-view images of microscopic and nanoscopic phenomena. Whether in the X-ray regime at third-generation synchrotron sources, in the electron microscope for atomic scale phenomena, or in the in the optical regime for biological samples, ptychography has shown an unparalleled ability to acquire hundreds of megapixels of sample information near the diffraction limit. Typically, the underlying operation of ptychography is to sample a series of diffraction patterns from a sample as it is scanned through a focused beam. These intensity-only measurements are then reconstructed into a complex (i.e. amplitude and phase), high-resolution image with more pixels of sample information than any single recorded diffraction pattern.
Recently, a Fourier ptychographic imaging technique was introduced that constructs a high-resolution sample complex, high-resolution image from a series of low-resolution intensity measurements captured while the sample of interest is sequentially illuminated from different incidence angles. In one particular implementation, a Fourier ptychographic microscopy (FPM) system uses an array of light emitting diodes (LEDs) located beneath, a thin, semi-transparent sample of interest. Each LED approximates a point illumination source. During image acquisition, the FPM system sequentially turns on individual LEDs to provide illumination incident to the sample from different angles. The light from each LED passes through the thin sample and to an imaging lens (e.g., a conventional microscope objective). The light detector receives diffraction patterns from the imaging lens and captures intensity measurements to form a unique lower resolution image for each incidence angle. The set of lower resolution images acquired during sequential illumination by different incidence angles can be reconstructed into a high-resolution complex measurement through a phase-retrieval operation. An example of this standard Fourier ptychographic imaging technique and an FPM system that implements this technique can be found in Zheng, Guoan, Horstmeyer, Roarke, and Yang, Changhuei, “Wide-field, high-resolution Fourier ptychographic microscopy,” Nature Photonics vol. 7, pp. 739-745 (2013) and in U.S. patent application Ser. No. 14/065,280, titled “Fourier Ptychographic Imaging Systems, Devices, and Methods” and filed on Oct. 28, 2013; which are hereby incorporated by reference in their entirety and for all purposes.